Insert

ABSTRACT

An insert may include a first surface, a second surface, a ridge line located at an intersection of the first surface and the second surface. The first surface may include a first corner, a first side and a second side. The ridge line may include a corner cutting edge located on the first corner, a first cutting edge located on the first side, and a second cutting edge located on the second side. The first surface may further include a first region located from the first cutting edge toward a midportion of the first surface, a second region located from the second cutting edge toward the midportion of the first surface, and a concave part located on at least one of the first region and the second region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.16/640,376 filed on Feb. 20, 2020 which is a national stage entryaccording to 35 U.S.C. 371 of PCT Application No. PCT/JP2018/031166,filed on Aug. 23, 2018, which claims priority to Japanese ApplicationNo. 2017-160268, filed on Aug. 23, 2017, which is entirely incorporatedherein by reference.

TECHNICAL FIELD

The present disclosure generally relates to inserts for use in a cuttingprocess. More specifically, the present disclosure relates to insertsused for rotary tools.

BACKGROUND

A cutting tool is discussed in Japanese Unexamined Patent PublicationNo. 2008-279519 (Patent Document 1) which is usable for a cuttingprocess of a workpiece. A cutting insert (an insert) of Patent Document1 has a polygonal plate shape and includes a cutting edge located on aridge line where a polygonal surface intersects with an outer peripheralsurface. The cutting tool of Patent Document 1 is usable for athree-dimensional process, such as ramping process.

SUMMARY

An insert in a non-limiting embodiment may include a first surface, asecond surface, and a ridge line where the first surface intersects withthe second surface. The first surface may include a first corner, afirst side extended from the first corner, and a second side extendedfrom the first corner. The ridge line may include a corner cutting edgelocated on the first corner, a first cutting edge located on at least apart of the first side, and a second cutting edge located on at least apart of the second side. The first surface may further include a firstregion located from the first cutting edge toward a midportion of thefirst surface, a second region located from the second cutting edgetoward the midportion of the first surface, and a concave part locatedon at least one of the first region and the second region.

An insert in a non-limiting embodiment may include a first surface, asecond surface, and a ridge line where the first surface intersects withthe second surface. The first surface may include a first corner, afirst side extended from the first corner, and a second side extendedfrom the first corner. The ridge line may include a corner cutting edgelocated on the first corner, a first cutting edge located on at least apart of the first side, and a second cutting edge located on at least apart of the second side. The first surface may further include a firstregion located from the first cutting edge toward a midportion of thefirst surface, a second region located from the second cutting edgetoward the midportion of the first surface, and a convex part located onat least one of the first region and the second region.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a cutting insert in anon-limiting embodiment;

FIG. 2 is a front view of the cutting insert illustrated in FIG. 1 asviewed from a side of a first surface;

FIG. 3 is a side view of the cutting insert illustrated in FIG. 2 asviewed from direction A1;

FIG. 4 is a side view of the cutting insert illustrated in FIG. 2 asviewed from direction A2;

FIG. 5 is an enlarged view of a region B1 in FIG. 2;

FIG. 6 is an enlarged view of a region B2 in FIG. 4;

FIG. 7 is a conceptual diagram of a cutting process using the cuttinginsert illustrated in FIG. 1;

FIG. 8 is a sectional view taken along line C1-C1 in FIG. 5;

FIG. 9 is a sectional view taken along line C2-C2 in FIG. 5;

FIG. 10 is a sectional view taken along line C3-C3 in FIG. 5;

FIG. 11 is an enlarged view of a cutting insert in a non-limitingembodiment;

FIG. 12 is a perspective view illustrating a cutting insert in anon-limiting embodiment;

FIG. 13 is a front view of the cutting insert illustrated in FIG. 12 asviewed from a side of a first surface;

FIG. 14 is a side view of the cutting insert illustrated in FIG. 13 asviewed from A3 direction;

FIG. 15 is a sectional view taken along line C4-C4 in FIG. 13;

FIG. 16 is an enlarged view of a region B3 in FIG. 14;

FIG. 17 is an enlarged view of a cutting insert in a non-limitingembodiment;

FIG. 18 is a perspective view illustrating a cutting tool in anon-limiting embodiment;

FIG. 19 is a side view of the cutting tool illustrated in FIG. 18;

FIG. 20 is a diagram illustrating one of the steps in a method formanufacturing a machined product in a non-limiting embodiment;

FIG. 21 is a diagram illustrating one of the steps in the method formanufacturing a machined product in the non-limiting embodiment; and

FIG. 22 is a diagram illustrating one of the steps in the method formanufacturing a machined product in the non-limiting embodiment.

DETAILED DESCRIPTION

<Cutting Inserts>

Cutting inserts (hereinafter also referred to simply as “inserts”) innon-limiting embodiments may be described in detail below with referenceto the drawings. For convenience of description, the drawings referredto in the following illustrate, in simplified form, only main membersnecessary for describing non-limiting embodiments. The inserts in thepresent disclosure may be therefore capable of including any arbitrarystructural member not illustrated in the drawings referred to.Dimensions of the members in each of the drawings may be ones whichfaithfully represent neither dimensions of actual structural members nordimension ratios of these members.

As illustrated in FIG. 1, the insert 1 in a non-limiting embodiment mayinclude a first surface 3 (an upper surface in FIG. 1), a second surface5 (a side surface in FIG. 1), and a ridge line 7 where the first surface3 intersects with the second surface 5. The first surface 3 may have apolygonal shape, and the first surface 3 may have an approximatelyhexagonal shape in a non-limiting embodiment illustrated in FIG. 2.Accordingly, the first surface 3 may include six corners and six sides.Because the first surface 3 has the approximately hexagonal shape, thesecond surface 5 may include six planar regions.

As illustrated in FIG. 2, the first surface 3 may include a first corner9, and a first side 11 and a second side 13 each extended from the firstcorner 9. The first corner 9 may be one of the six corners included inthe first surface 3 in FIG. 2. The first side 11 and the second side 13may be two of the six sides included in the first surface 3. The firstcorner 9 may be rephrased as a protruded part protruded in a directionaway from a midportion of the first surface 3 in a front view of thefirst surface 3.

The first surface 3 may have an approximately polygonal shape and neednot be a strict polygonal shape. Specifically, the sides in the firstsurface 3 having the polygonal shape need not have a strict straightline shape or, alternatively, these sides may have, for example, aconvex curvilinear shape or concave curvilinear shape. The corners inthe first surface 3 having the polygonal shape are not limited to astructure formed by intersection of two straight lines, but may have,for example, an outwardly rounded shape.

The shape of the first surface 3 is not limited to the aboveconfiguration. There is no problem even if the first surface 3 has aquadrangular shape, pentagonal shape or octagonal shape instead of thehexagonal shape. Dimensions of the insert 1 are not particularlylimited. For example, a maximum width of the first surface 3 may be setto, approximately 3-20 mm. A height from the first surface 3 to thethird surface 6 may be set to approximately 5-20 mm.

Alternatively, the insert 1 may include a hole 39 that opens into thefirst surface 3. The hole 39 may penetrate through the third surface 6located on opposite side of the first surface 3. The hole 39 is notlimited to the above embodiment but may open into the second surface 5.For example, the hole 39 may be configured to penetrate through the twoplanar regions located opposite sides on the second surface.

The hole 39 may be used as an insertion hole for a fixing tool whenattaching the insert 1 to a holder. Examples of the fixing tool mayinclude a screw and a wedge. Alternatively, the insert 1 may be fixed tothe holder by using a brazing material.

The insert 1 may include a cutting edge located at least on a part ofthe ridge line 7 in a non-limiting embodiment. Specifically, the ridgeline 7 may include a corner cutting edge 15 located on the first corner9, a first cutting edge 17 located on at least a part of the first side11, and a second cutting edge 19 located on at least the second side 13.The first cutting edge 17 may connect to the corner cutting edge 15. Thesecond cutting edge 19 may connect to the corner cutting edge 15.

The first cutting edge 17 may be located on only the part or the wholeof the first side 11. The second cutting edge 19 may be located on onlythe part or the whole of the second side 13. A so-called honing processmay be applied to the corner cutting edge 15, the first cutting edge 17and the second cutting edge 19. In other words, the ridge line 7 wherethe first surface 3 intersects with the second surface 5 may not be astrict line shape obtained by intersection of the two surfaces.

The first surface 3 may also include a first region 21 located from thefirst cutting edge 17 toward a midportion of the first surface 3, and asecond region 23 located from the second cutting edge 19 toward themidportion of the first surface 3. The first region 21 and the secondregion 23 may serve as a rake surface.

The first surface 3 may include a concave part 25 located in at leastone of the first region 21 and the second region 23. The first surface 3may include the concave part 25 extended from a side of the ridge line 7toward the midportion of the first surface 3 in FIGS. 1 to 6. FIGS. 1 to6 may illustrate a non-limiting embodiment in which the concave part 25is located in the first region 21.

The term “toward the midportion of the first surface 3” may denote“toward the midportion of the first surface 3 in a front view from theridge line 7 of the first surface 3,” but need not be strictly directedtoward the midportion of the first surface 3 in a non-limitingembodiment.

With the insert 1 including the above configuration in a non-limitingembodiment, when chips generated by the part of the ridge line 7, whichserves as the cutting edge during a cutting process, flow toward themidportion of the first surface 3, the chips may be bent upon contactwith the concave part 25. The chips may be likely to be divided apartfrom a portion thus bent.

FIG. 7 may illustrate an example of how the chips are divided apart bythe contact with the concave part 25. The chips may be divided apartalong a chip extending direction in the example illustrated in FIG. 7.The chips so divided apart may have a small width. The chips having thesmall width may tend to be curled while being grazed on the firstsurface 3. The curled chips may tend to be well divided apart. The chipsmay be less likely to extend long because the chips are divided apart.This may make it easier for the chips to be discharged well. Chipclogging may be less likely to occur because of good chip dischargeperformance. Additionally, a machined surface is less susceptible todamage due to the chips.

Upon the contact with the concave part 25, chips may be divided apart ina direction orthogonal to the chip extending direction. This may bebecause the chips become less likely to be curled due to bending by thecontact with the concave part 25. The chips less likely to be curled mayfurther be bent in the direction orthogonal to the chip extendingdirection. The chips may tend to be divided apart from a bent portion inthe direction orthogonal to the chip extending direction. In otherwords, the chips may be less likely to be curled and may be dividedapart at short intervals in the chip extending direction. The chips thusdivided in short lengths may tend to be discharged well.

If the concave part 25 is extended from the side of the ridge line 7toward the midportion of the first surface 3, the concave part 25 mayserve as a chip flow guide, thus leading to a better chip discharge.

No particular limitations may be imposed on a length N1 of the concavepart 25 in a direction orthogonal to the first cutting edge 17 in caseswhere the concave part 25 is located in the first region 21. Forexample, a portion having a maximum length N1 may be expressed by 0.03M1 to 0.24 M1 where M1 is a length of the first cutting edge 17.

Similarly, no particular limitations may be imposed on a length N2 ofthe concave part 25 in a direction orthogonal to the second cutting edge19 in cases where the concave part 25 is located in the second region23. For example, a portion having a maximum length N2 may be expressedby 0.03 M2 to 0.24 M2 where M2 is a length of the second cutting edge19.

The concave part 25 may be located in one of the first region 21 and thesecond region 23. Alternatively, the concave part 25 may be located inboth the first region 21 and the second region 23. The concave part 25may be located in the first region 21 in a non-limiting embodimentillustrated in FIG. 2 as described above.

For example, the first cutting edge 17 on the ridge line 7 is capable ofserving as an inner peripheral cutting edge, and the second cutting edge19 on the ridge line 7 is capable of serving as an outer peripheralcutting edge. In this case, the second cutting edge 19 is usable mainlyduring a face milling process. In addition to the second cutting edge19, the first cutting edge 17 is also usable during a ramping process.

In cases where the concave part 25 is located in the first region 21 asin a non-limiting embodiment illustrated in FIG. 2, good chip dischargeperformance is attainable.

Chips generated by the first cutting edge 17 serving as the innerperipheral cutting edge may be relatively thin, and therefore, a flow ofthe chips generated by the first cutting edge 17 may become unstable andmay be liable to extend long. However, the chips generated by the firstcutting edge 17 can be stably divided apart if the concave part 25 islocated in the first region 21.

A good machined surface is obtainable if the concave part 25 is locatedin the second region 23. Chips generated by the second cutting edge 19serving as the outer peripheral cutting edge may be relatively thick,and the machined surface is therefore susceptible to damage uponoccurrence of chip clogging. However, the chips generated by the secondcutting edge 19 can be stably divided apart if the concave part 25 islocated in the second region 23. Consequently, the chip clogging may beless likely to occur, thus leading to the good machined surface.

The above effects are obtainable and the good chip discharge performanceis attainable if the concave part 25 is located in both the first region21 and the second region 23.

The concave part 25 may be located away from the ridge line 7, oralternatively, may include a part of the ridge line 7 as illustrated inFIG. 1 or the like. In other words, the concave part 25 may open intothe second surface 5. In this case, the concave part 25 may extend fromthe ridge line 7 toward the midportion of the first surface 3.

In cases where the concave part 25 thus opens into the second surface 5,the first side 11 may have a concave shape in a front view of the secondsurface 5 as illustrated in FIG. 4, and therefore, the chips may tend tocome into contact with the concave part 25. Consequently, the chipsgenerated by the first cutting edge 17 may tend to be bent and dividedapart.

The concave part 25 may include a part thereof whose width in adirection along the ridge line 7 becomes smaller as going away from theridge line 7 in the front view of the first surface 3 as in anon-limiting embodiment illustrated in FIG. 5. Specifically, forexample, if the concave part 25 is located in the first region 21, theconcave part 25 may include a part thereof whose width W1 in a directionalong the first cutting edge 17 becomes smaller as going away from thefirst cutting edge 17 in the front view of the first surface 3.Alternatively, the concave part 25 may be configured so that the widthW1 becomes smaller as a whole as going away from the first cutting edge17.

The chip discharge performance can be further enhanced if the concavepart 25 is configured as described above. This may be because the chipscan easily graze through the concave part 25 when being bent at theconcave part 25. The chips may be therefore less likely to beaccumulated in the concave part 25, thus leading to further enhancedchip discharge performance.

The length of the width W1 is not particularly limited. For example, aportion having a maximum length W1 may be expressed by 0.1 M1 to 0.8 M1where M1 is a length of the first cutting edge 17.

The concave part 25 may include a part that becomes shallower as goingaway from the ridge line 7 as in a non-limiting embodiment illustratedin FIG. 8. Further enhanced chip discharge performance is alsoattainable even if the concave part 25 is configured as described above.The chip discharge performance can be further enhanced because the chipsare less likely to be accumulated in the concave part 25. The term“becoming shallower” may denote that a distance D1 between a bottomportion of the concave part 25 and a reference plane S1 orthogonal to acentral axis P of the insert 1 becomes smaller as going away from theridge line 7.

Although the bottom portion of the concave part 25 continuously becomesshallower in a non-limiting embodiment illustrated in FIG. 8, it may notbe intended to limit to this embodiment. The concave part 25 may includea part thereof where the distance between the bottom portion of theconcave part 25 and the reference plane S1 is constant.

The length of the distance D1 is not particularly limited. For example,a portion having a maximum distance D1 may be expressed by 0.01 M1 to0.4 M1 where M1 is the length of the first cutting edge 17.

In cases where the concave part 25 opens into the second surface 5, theridge line located on both sides of the concave part 25 may correspondto a first ridge line 27 and a second ridge line 29, a part of the firstsurface 3 which is located from the first ridge line 27 toward themidportion of the first surface 3 may be a third region 33, and a partof the first surface 3 which is located from the second ridge line 29toward the midportion of the first surface 3 may be a fourth region 35.The third region 33 and the fourth region 35 may serve as a rakesurface.

In a non-limiting embodiment illustrated in FIG. 5, a part of the firstcutting edge 17 which is located more away from the first corner 9 thanthe concave part 25 may correspond to the first ridge line 27. A part ofthe first cutting edge 17 which is located closer to the first corner 9than the concave part 25 may correspond to the second ridge line 29. Apart of the first region 21 which is located along the first ridge line27 may correspond to the third region 33. A part of the first region 21which is located along the second ridge line 29 may correspond to thefourth region 35.

An angle formed by the third region 33 and the reference plane S2orthogonal to the central axis P of the insert 1 may be a first angleθ1. An angle formed by the reference plane S1 and the fourth region 35may be a second angle θ2. A value of the first angle θ1 may be identicalwith or different from a value of the second angle θ2. The second angleθ2 may be larger than the first angle θ1 in a non-limiting embodimentillustrated in FIGS. 9 and 10.

If the first angle θ1 is different from the second angle θ2, a part ofchips which flows through the third region 33 may be different from theother part flowing through the fourth region 35 in chip flow velocity.Accordingly, the part of the chip bent by the concave part 25 may tendto be easily divided apart due to velocity differences between chipsflowing through the third region 33 and the chips flowing through thefourth region 35.

In a front view of the second surface 5, the first ridge line 27 and thesecond ridge line 29 may be located on an imaginary straight line.Alternately, an imaginary extension line L1 of the first ridge line 27may intersect with an imaginary extension line L2 of the second ridgeline 29 as in a non-limiting embodiment illustrated in FIG. 6.

A portion indicated by an imaginary straight line L3 that connects anintersection point of the concave part 25 and the first ridge line 27and an intersection point of the concave part 25 and the second ridgeline 29 may be an opening of the concave part 25 in the front view ofthe second surface 5. If the imaginary extension line L1 is locatedcloser to the bottom portion of the concave part 25 than the opening asillustrated in FIG. 6, a ridge portion where the concave 25 intersectswith the first ridge line 27 may have a large angle, and a large cuttingload may be therefore less likely to be concentrated at the ridge part.Consequently, the insert 1 may be less subject to fractures, thusleading to enhanced durability of the insert 1.

If the imaginary extension line L1 is located further away from thebottom portion of the concave part 25 than the opening as illustrated inFIG. 11, a ridge portion where the concave 25 intersects with the firstridge line 27 may have a small angle. Hence, the part of the chips whichflows through the third region 33 may be more likely to be bent than thepart of the chips which flows through the concave 25. The chips may betherefore more likely to be divided apart. FIG. 11 may be an enlargedview of a region corresponding to FIG. 6 in the inert 1 in anon-limiting embodiment.

If the imaginary extension line L2 is located further away from thebottom portion of the concave part 25 than the opening as illustrated inFIG. 11, a ridge portion where the concave 25 intersects with the secondridge line 29 may have a small angle. Hence, the part of the chips whichflows through the fourth region 35 may be more likely to be bent thanthe part of the chips which flows through the concave 25. The chips maybe therefore more likely to be divided apart.

If the imaginary extension line L2 is located closer to the bottomportion of the concave part 25 than the opening, a ridge portion wherethe concave 25 intersects with the second ridge line 29 may have a largeangle. Hence, a large cutting load may be less likely to be concentratedat the ridge part. The insert 1 may be therefore less subject tofractures, thus leading to enhanced durability of the insert 1.

In a non-limiting embodiment illustrated in FIG. 11, the imaginaryextension line L1 intersects with the imaginary extension line L2, andthe imaginary extension line L1 and the imaginary extension line L2 maybe located further away from the bottom portion of the concave part 25than the opening. In this case, chips may be more likely to be dividedapart, thus leading to more improved chip discharge performance.

A length of the first ridge line 27 and a length of the second ridgeline 29 are not limited to a specific value. For example, the firstridge line 27 may have the same length as the second ridge line 29, oralternatively, the length of the first ridge line 27 may be differentfrom the length of the second ridge line 29.

For example, cemented carbide or cermet is usable as a material of theinsert 1. Examples of composition of the cemented carbide may includeWC—Co, WC—TiC—Co and WC—TiC—TaC—Co. The WC—Co may be produced by addingcobalt (Co) powder to tungsten carbide (WC), followed by sintering. TheWC—TiC—Co may be produced by adding titanium carbide (TiC) to WC—Co. TheWC—TiC—TaC—Co may be produced by adding tantalum carbide (TaC) toWC—TiC—Co.

The cermet may be a sintered composite material obtainable bycompositing metal into a ceramic component. Examples of the cermet mayinclude ones which are composed mainly of a titanium compound, such astitanium carbide (TiC) or titanium nitride (TiN).

A surface of the insert 1 may be coated with a coating film by using achemical vapor deposition (CVD) method or a physical vapor deposition(PVD) method. Examples of composition of the coating film may includetitanium carbide (TiC), titanium nitride (TiN), titanium carbonitride(TiCN) and alumina (Al₂O₃).

Another cutting insert 1′ in a non-limiting embodiment may be describedbelow with reference to the drawings. The following description of theinsert 1′ may be focused on differences from the insert 1. Therefore,the insert 1′ may include configurations similar to those in the insert1. Descriptions of the similar configurations may be omitted in somecases.

As illustrated in FIG. 12, the insert 1′ in a non-limiting embodimentmay include a first surface 3 (an upper surface in FIG. 12), a secondsurface 5 (a side surface in FIG. 12), and a ridge line 7 where thefirst surface 3 intersects with the second surface 5. The first surface3 may have a polygonal shape, and the first surface 3 may have anapproximately hexagonal shape in a non-limiting embodiment illustratedin FIG. 13. Accordingly, the first surface 3 may include six corners andsix sides.

As illustrated in FIG. 13, the first surface 3 may include a firstcorner 9, and a first side 11 and a second side 13 each extended fromthe first corner 9. The first corner 9 may be one of the six cornersincluded in the first surface 3 in FIG. 13. The first side 11 and thesecond side 13 may be two of the six sides included in the first surface3.

The first surface 3 may have an approximately polygonal shape and neednot be a strict polygonal shape. Specifically, the sides in the firstsurface 3 having the polygonal shape need not have a strict straightline shape or, alternatively, these sides may have, for example, aconvex curvilinear shape or concave curvilinear shape. The corners inthe first surface 3 having the polygonal shape are not limited to astructure formed by intersection of the two straight lines, but mayhave, for example, an outwardly rounded shape.

The shape of the first surface 3 is not limited to the aboveconfiguration. There is no problem even if the first surface 3 has aquadrangular shape, pentagonal shape or octagonal shape instead of thehexagonal shape.

The insert 1′ of a non-limiting embodiment may include a cutting edgelocated on at least a part of the ridge line 7 in a non-limitingembodiment. Specifically, the ridge line 7 may include a corner cuttingedge 15 located on the first corner 9, a first cutting edge 17 locatedon at least a part of the first side 11, and a second cutting edge 19located on at least the second side 13.

The first cutting edge 17 may be located on only the part or the wholeof the first side 11. The second cutting edge 19 may be located on onlythe part or the whole of the second side 13. A so-called honing processmay be applied to the corner cutting edge 15, the first cutting edge 17and the second cutting edge 19. In other words, the ridge line 7 wherethe first surface 3 intersects with the second surface 5 may not be astrict line shape obtained by intersection of the two surfaces.

The first surface 3 may also include a first region 21 located from thefirst cutting edge 17 toward a midportion of the first surface 3, and asecond region 23 located from the second cutting edge 19 toward themidportion of the first surface 3. The first region 21 and the secondregion 23 may serve as a rake surface.

The first surface 3 may include a convex part 37 located in at least oneof the first region 21 and the second region 23. The first surface 3 mayinclude the convex part 37 extended from a side of the ridge line 7toward the midportion of the first surface 3 in FIGS. 12 to 14. Inshort, the insert 1 may include the concave part 25 in the aboveembodiment, while the insert 1′ may include the convex part 37 in anon-limiting embodiment as a configuration corresponding to the concavepart 25. FIGS. 12 to 14 may illustrate a non-limiting embodiment inwhich the convex part 37 is located in the first region 21.

With the insert 1′ including the convex part 37 in a non-limitingembodiment, when chips generated by the part of the ridge line 7 whichserves as the cutting edge flow toward the midportion of the firstsurface 3 during a cutting process, the chips may be bent upon contactwith the convex part 37. The chips may be likely to be divided apartfrom a portion thus bent.

In an example of how the chips are divided apart by the contact with theconvex part 37, the chips may be divided apart along a chip extendingdirection. The chips so divided apart may have a small width. The chipshaving the small width may tend to be curled while being grazed on thefirst surface 3. The curled chips may tend to be well divided apart. Thechips may be less likely to extend long because the chips are dividedapart. This may lead to good discharge of the chips. Chip clogging maybe less likely to occur because of good chip discharge performance.Additionally, a machined surface is less susceptible to damage due tothe chips.

Upon the contact with the convex part 37, chips may be divided apart ina direction orthogonal to the chip extending direction. This may bebecause the chips become less likely to be curled due to bending by thecontact with the convex part 37. The chips less likely to be curled mayfurther be bent in the direction orthogonal to the chip extendingdirection. The chips may tend to be divided apart from a bent portion inthe direction orthogonal to the chip extending direction. In otherwords, the chips may be less likely to be curled and may be dividedapart at short intervals in the chip extending direction. Thus, thechips thus divided in short lengths may tend to be discharged easily.

If the convex part 37 is extended from a side of the ridge line 7 towardthe midportion of the first surface 3, the convex part 37 may serve as achip flow guide, thereby contributing to a better chip discharge.

No particular limitations may be imposed on a length N3 of the convexpart 37 in a direction orthogonal to the first cutting edge 17 in caseswhere the convex part 37 is located in the first region 21. For example,a portion having a maximum length N3 may be expressed by 0.03 M1 to 0.24M1 where M1 is a length of the first cutting edge 17.

Similarly, no particular limitations may be imposed on a length N4 ofthe convex part 37 in a direction orthogonal to the second cutting edge19 in cases where the convex part 37 is located in the second region 23.For example, a portion having a maximum length N4 may be expressed by0.03 M2 to 0.24 M2 where M2 is a length of the second cutting edge 19.

The convex part 37 may be located in one of the first region 21 and thesecond region 23. Alternatively, the convex part 37 may be located inboth the first region 21 and the second region 23. The convex part 37may be located in the first region 21 in a non-limiting embodimentillustrated in FIG. 13 as described above.

For example, the first cutting edge 17 on the ridge line 7 is capable ofserving as an inner peripheral cutting edge, and the second cutting edge19 on the ridge line 7 is capable of serving as an outer peripheralcutting edge. In this case, the second cutting edge 19 is usable mainlyduring a face milling process. In addition to the second cutting edge19, the first cutting edge 17 is also usable during a ramping process.

In cases where the convex part 37 is located in the first region 21 asin a non-limiting embodiment illustrated in FIG. 13, good chip dischargeperformance is attainable.

Chips generated by the first cutting edge 17 serving as the innerperipheral cutting edge may be relatively thin, and therefore, a flow ofthe chips generated by the first cutting edge 17 may become unstable andmay be liable to extend long. However, the chips generated by the firstcutting edge 17 can be stably divided apart if the convex part 37 islocated in the first region 21.

A good machined surface is obtainable if the convex part 37 is locatedin the second region 23. Chips generated by the second cutting edge 19serving as the outer peripheral cutting edge may be relatively thick,and the machined surface is therefore susceptible to damage uponoccurrence of chip clogging. However, the chips generated by the secondcutting edge 19 can be stably divided apart if the convex part 37 islocated in the second region 23. Consequently, the chip clogging may beless likely to occur, thus leading to the good machined surface.

The above effects may be obtainable and the good chip dischargeperformance is attainable if the concave part 25 is located in both thefirst region 21 and the second region 23.

The convex part 37 may be located away from the ridge line 7, oralternatively, may include a part of the ridge line 7 as illustrated inFIG. 12. If the convex part 37 includes the part of the ridge line 7,the first cutting edge 17 may have a convex shape in the front view ofthe second surface 5. In this case, the convex part 37 may extend fromthe ridge line 7 toward the midportion of the first surface 3.

In cases where the convex part 37 is thus in contact with the ridge line7, the first side 11 may have a convex shape in the front view of thesecond surface 5, and therefore, chips may tend to come into contactwith the convex part 37. Consequently, the chips generated by the firstcutting edge 17 may tend to be bent and divided apart.

The convex part 37 may include a part thereof whose width in a directionalong the ridge line 7 becomes smaller as going away from the ridge line7 in the front view of the first surface 3 as illustrated in FIG. 13.Specifically, for example, if the convex part 37 is located in the firstregion 21, the convex part 37 may include a part thereof whose width W2in a direction along the first cutting edge 17 becomes smaller as goingaway from the first cutting edge 17 in the front view of the firstsurface 3. Alternatively, the convex part 37 may be configured so thatthe width W2 becomes smaller as a whole as going away from the firstcutting edge 17.

In cases where the convex part 37 includes the above configuration,stress concentration at a part of the convex part 37 which is in contactwith the ridge line 7 can be relaxed to improve durability of the convexpart 37.

The length of the width W2 is not particularly limited. For example, aportion having a maximum length W1 may be expressed by 0.1 M1 to 0.8 M1where M1 is a length of the first cutting edge 17.

The convex part 37 may include a part thereof where a height of theconvex part 37 becomes smaller as going away from the ridge line 7 asillustrated in FIG. 15. Further enhanced chip discharge performance isalso attainable even if the convex part 37 is configured as describedabove. The chip discharge performance can be further enhanced becausethe chips are less likely to be accumulated in the convex part 37. Thephrase “height becomes smaller” may denote that a distance D2 between atop portion of the convex part 37 and the reference plane S1 orthogonalto the central axis P of the insert becomes smaller as going away fromthe ridge line 7.

Although the top portion of the convex part 37 continuously may becomelower in a non-limiting embodiment illustrated in FIG. 15, it may not beintended to limit to this embodiment. The convex part 37 may include apart thereof where the distance between the top portion of the convexpart 37 and the reference plane S1 is constant.

The length of the distance D2 is not particularly limited. For example,a portion having a maximum distance D2 may be expressed by 0.01 M1 to0.4 M1 where M1 is the length of the first cutting edge 17.

In cases where the convex part 37 is in contact with the ridge line 7,the ridge line located on both sides of the convex part 37 maycorrespond to a first ridge line 27′ and a second ridge line 29′, a partof the first surface 3 which is located from the first ridge line 27′toward the midportion of the first surface 3 may be a third region 33′,and a part of the first surface 3 which is located from the second ridgeline 29′ toward the midportion of the first surface 3 may be a fourthregion 35′. The third region 33′ and the fourth region 35′ may serve asa rake surface.

A part of the first cutting edge 17 which is located more away from thefirst corner 9 than the convex part 37 may correspond to the first ridgeline 27′. A part of the first cutting edge 17 which is located closer tothe first corner 9 than the convex part 37 may correspond to the secondridge line 29′. A part of the first region 21 which is located along thefirst ridge line 27′ may correspond to the third region 33′. A part ofthe first region 21 which is located along the second ridge line 29′ maycorrespond to the fourth region 35′.

An angle formed by the third region 33′ and the reference plane S1orthogonal to the central axis P of the insert 1′ may be a first angleθ1′. An angle formed by the reference plane S1 and the fourth region 35′may be a second angle θ2′. A value of the first angle θ1′ may beidentical with or different from a value of the second angle θ2′. Forexample, the second angle θ2′ may be larger than the first angle θ1′.

If the first angle θ1′ is different from the second angle θ2′, a part ofchips flowing through the third region 33′ may be different from theother part flowing through the fourth region 35′ in chip flow velocity.Accordingly, the part of the chip bent by the convex part 37 may tend tobe torn off and divided apart due to velocity differences between chipsflowing through the third region 33′ and chips flowing through thefourth region 35′.

In the front view of the second surface 5, the first ridge line 27′ andthe second ridge line 29′ may be located on an imaginary straight line.Alternately, an imaginary extension line L1 of the first ridge line 27′may intersect with an imaginary extension line L2 of the second ridgeline 29′ as in a non-limiting embodiment illustrated in FIG. 16.

A portion indicated by an imaginary straight line L4 that connects anintersection point of the convex part 37 and the first ridge line 27′and an intersection point of the convex part 37 and the second ridgeline 29′ may be a bottom portion of the convex part 37 in the front viewof the second surface 5. If the imaginary extension line L1 is locatedcloser to the top portion of the convex part 37 than the bottom portionof the convex part 37 as in a non-limiting embodiment illustrated inFIG. 17, chip clogging may be less likely to occur in the vicinity of aboundary between the convex part 37 and the first ridge line 27′. FIG.17 may be an enlarged view of a region in the insert 1 in a non-limitingembodiment which corresponds to FIG. 16.

If the imaginary extension line L1 is located further away from the topportion of the convex part 37 than the bottom portion of the convex part37 as in a non-limiting embodiment illustrated in FIG. 16, chips may belikely to be bent in the vicinity of the boundary between the convexpart 37 and the first ridge line 27′. The chips may be therefore morelikely to be divided apart.

If the imaginary extension line L2 is located closer to the top portionof the convex part 37 than the bottom portion of the convex part 37 asin a non-limiting embodiment illustrated in FIG. 17, chip clogging maybe less likely to occur in the vicinity of the boundary between theconvex part 37 and the second ridge line 29′.

If the imaginary extension line L2 is located further away from the topportion of the convex part 37 than the bottom portion of the convex part37, chips may be likely to be bent in the vicinity of a boundary betweenthe convex part 37 and the second ridge line 29′. The chips may betherefore more likely to be divided apart.

In a non-limiting embodiment illustrated in FIG. 17, the imaginaryextension line L1 may intersect with the imaginary extension line L2,and the imaginary extension line L1 and the imaginary extension line L2may be located closer to the top portion of the convex part 37 than thebottom portion of the convex part 37. If the imaginary extension line L1and the imaginary extension line L2 are located as described above, chipclogging may be much less likely to occur in the vicinity of theboundary between the concave part 37 and the first ridge line 27′ and inthe vicinity of the boundary between the convex part 37 and the secondridge line 29′.

A length of the first ridge line 27′ and a length of the second ridgeline 29′ are not limited to a specific value. For example, the firstridge line 27′ may have the same length as the second ridge line 29′.Alternatively, the length of the first ridge line 27′ may be differentfrom the length of the second ridge line 29′.

<Cutting Tool>

A cutting tool in a non-limiting embodiment of the present disclosuremay be described below with reference to the drawings. FIGS. 18 and 19may illustrate a state in which the insert 1 illustrated in FIG. 1 isattached to an insert pocket 105 (hereinafter also referred to simply as“pocket 105”) of a holder 103 by a screw 107. A rotation axis X of thecutting tool 101 may be indicated by a two-dot chain line in FIG. 18 orthe like.

The cutting tool 101 of a non-limiting embodiment is usable for amilling process. As illustrated in FIG. 18 or the like, the cutting tool101 may have the rotation axis X1 and may include the holder 103 with aplurality of pockets 105 on an outer peripheral surface at a side of afront end of the cutting tool 101, and inserts represented by theforegoing non-limiting embodiment which are individually attached to thepockets 105. The insert 1 in the above embodiment may be illustrated asthe inserts in FIGS. 18 and 19.

The holder 103 may be a bar-shaped body extended from a first end (lowerleft end in FIG. 18) to a second end (upper right end in FIG. 18). Theplurality of pockets 105 may be located on an outer peripheral surfaceat a side of the first end of the holder 103. The pockets 105 may beparts that respectively permit attachment of the inserts 1 and open intoan outer peripheral surface and the first end of the holder 103.

The pockets 105 may be disposed at equal or unequal intervals along arotation direction Y of the rotation axis X. The holder 103 may includethe pockets 103 formed therein, and therefore may not have a strictcylindrical shape.

Each of the inserts 1 is attachable to the pockets 105 by the screw 107.That is, the insert 1 is attachable to the holder 103 by inserting thescrew 107 into a through hole of the insert 1, and by inserting a frontend of the screw 107 into a screw hole formed in the pocket 105 so as tofix the screw 107 to the screw hole.

Steel or cast iron is usable for the holder 103. Of these materials,high-toughness steel may be particularly used. There is no problem evenif the cutting tool 101 includes the inserts 1′ of a non-limitingembodiment instead of the inserts 1 of a non-limiting embodiment.

<Method for Manufacturing Machined Product>

A method for manufacturing a machined product in non-limitingembodiments of the present disclosure may be described below withreference to the drawings.

The machined product is manufacturable by carrying out a cutting processof a workpiece. The method for manufacturing a machined product in anon-limiting embodiment may include the following steps:

the step (1) of rotating the cutting tool 101 represented by the aboveembodiments;

the step (2) of bringing the cutting edge in the cutting tool 101 beingrotated into contact with the workpiece 201; and

the step (3) of moving the cutting tool 101 away from the workpiece 201.

More specifically, firstly, the rotary tool 101 may be rotated aroundthe rotation axis X and in the rotation direction Y, and the cuttingtool 101 may be relatively brought near the workpiece 201 as illustratedin FIG. 20. Subsequently, the workpiece 201 may be cut out by bringingat least one of the first cutting edge and the second cutting edge inthe cutting tool 101 being rotated into contact with the workpiece 201as illustrated in FIG. 21. The cutting tool 101 may be then relativelymoved away from the workpiece 201 as illustrated in FIG. 22. In order tofacilitate visual understanding, a region of the workpiece 201 cut outby the cutting tool 101 may be indicated by slant lines in FIGS. 21 and22.

In a non-limiting embodiment illustrated in FIG. 20, the cutting tool101 may be brought near the workpiece 201 by being moved in a Z1direction along the rotation axis X in a state in which the workpiece201 is fixed and the cutting tool 101 may be rotated. In FIG. 21, theworkpiece 201 may be cut out by bringing at least one of the cornercutting edge, the first cutting edge and the second cutting edge in thecutting tool 101 into contact with the workpiece 201 while the cuttingtool 101 being rotated is moved in a Z2 direction. In FIG. 22, thecutting tool 101 being rotated may be moved away by being moved in a Z3direction.

In a non-limiting embodiment illustrated in FIG. 21, the Z2 directionmay be not a direction orthogonal to the Z1 direction but a directioninclined relative to the Z1 direction. If the Z2 direction is thusinclined relative to the Z1 direction, a ramping process can be carriedout. If the Z2 direction is a direction orthogonal to the Z1 direction,a flattening process can be carried out.

In the cutting process with the manufacturing method of a non-limitingembodiment, the cutting tool 101 may be brought into contact with theworkpiece 201, or the cutting tool 101 may be moved away from theworkpiece 201 by moving the cutting tool 101 in the individual steps. Itmay, of course, not be intended to limit to this embodiment.

For example, the workpiece 201 may be brought near the cutting tool 101in the step (1). Similarly, the workpiece 201 may be moved away from thecutting tool 101 in the step (3). If desired to continue the cuttingprocess, the step of bringing the cutting edges in the cutting tool 101into contact with different portions of the workpiece 201 may berepeated while keeping the cutting tool 101 rotated.

Examples of material of the workpiece 201 may include carbon steel,alloy steel, stainless steel, cast iron and nonferrous metals.

Non-limiting embodiments in the present disclosure have been illustratedand described above. However, the present disclosure is not limited tothe foregoing embodiments. Non-limiting embodiments may include anyarbitrary configuration without departing from the gist of the presentdisclosure.

DESCRIPTION OF THE REFERENCE NUMERAL

-   -   1, 1′ insert    -   3 first surface    -   5 second surface    -   6 third surface    -   7 ridge line    -   9 first corner    -   11 first side    -   13 second side    -   15 corner cutting edge    -   17 first cutting edge    -   19 second cutting edge    -   21 first region    -   23 second region    -   25 concave part    -   27, 27′ first ridge line    -   29, 29′ second ridge line    -   33, 33′ third region    -   35, 35′ fourth region    -   37 convex part    -   39 hole    -   101 cutting tool    -   103 holder    -   105 pocket    -   107 screw    -   201 workpiece    -   θ1 first angle    -   θ2 second angle    -   P central axis of insert    -   S1 reference plane    -   X rotation axis    -   Y rotation direction    -   L1 imaginary extension line    -   L2 imaginary extension line    -   L3 imaginary straight line    -   L4 imaginary straight line

1. An insert, comprising: a first surface; a second surface; and a ridgeline located at an intersection of the first surface and the secondsurface, wherein the first surface comprises a first corner, a firstside extended from the first corner, and a second side extended from thefirst corner, the ridge line comprises a corner cutting edge located onthe first corner, a first cutting edge located on the first side, and asecond cutting edge located on the second side, and the first surfacefurther comprises a first region located from the first cutting edgetoward a midportion of the first surface, a second region located fromthe second cutting edge toward the midportion of the first surface, anda concave part located on at least one of the first region and thesecond region.
 2. The insert according to claim 1, wherein the concavepart comprises a part of the ridge line.
 3. The insert according toclaim 1, wherein the concave part comprises a part that becomes narroweras going away from the ridge line.
 4. The insert according to claim 1,wherein the concave part comprises a part that becomes shallower asgoing away from the ridge line.
 5. The insert according to claim 1,wherein parts of the ridge line located on both sides of the concavepart are a first ridge line and a second ridge line, a part of the firstsurface located from the first ridge line toward the midportion of thefirst surface is a third region, a part of the first surface locatedfrom the second ridge line toward the midportion of the first surface isa fourth region, an angle formed by the third region and a referenceplane orthogonal to a central axis of the insert is a first angle, andan angle formed by the fourth region and the reference plane is a secondangle, and a value of the first angle is different from a value of thesecond angle.
 6. An insert, comprising: a first surface; a secondsurface; and a ridge line located at an intersection of the firstsurface and the second surface, wherein the first surface comprises afirst corner, a first side extended from the first corner, and a secondside extended from the first corner, the ridge line comprises a cornercutting edge located on the first corner, a first cutting edge locatedon the first side, and a second cutting edge located on the second side,and the first surface further comprises a first region located from thefirst cutting edge toward a midportion of the first surface, a secondregion located from the second cutting edge toward the midportion of thefirst surface, and a convex part located on at least one of the firstregion and the second region.
 7. The insert according to claim 6,wherein the convex part connects to the second surface.
 8. The insertaccording to claim 6, wherein the convex part comprises a part thatbecomes narrower as going away from the ridge line.